Vehicles such as electric vehicles (EV) and plug-in hybrid vehicles (PHV) include an electricity storage device for storing electric power to be supplied to the drive motor. The electricity storage device is a rechargeable battery in this case. Typically, the rechargeable battery includes a case for accommodating an electrode assembly and an electrode assembly accommodated in the case. Electric power is taken out from the rechargeable battery through electrode terminals connected to positive electrodes and negative electrodes of the electrode assembly via conductive members.
Examples of the electrode assembly include a stacked electrode assembly, in which positive electrodes and negative electrodes are stacked with separators in between, and a spiral-type electrode assembly, in which a band-like positive electrode and a band-like negative electrode are wound with a band-like separator located in between.
As shown in FIG. 19, a rechargeable battery 80 of Patent Document 1 includes an electrode assembly 89, which is accommodated in a case 88. The electrode assembly 89 includes positive electrodes 81 and negative electrodes 82. Each positive electrode 81 includes a non-illustrated positive tab, and each negative electrode 82 includes a negative tab 82a. Although not shown, the positive tabs are electrically connected to a positive conductive member in a state in which the positive tabs are stacked into a tab bundle. The positive conductive member is connected to a positive electrode terminal. The negative tabs 82a are electrically connected to a negative conductive member 83 in a state in which the negative tabs 82a are stacked into a tab bundle. The negative conductive member 83 is electrically connected to a negative electrode terminal 84. Each electrode terminal 84, which is connected to the associated conductive member, is secured to a lid in a state in which the electrode terminal 84 extends through the lid, which forms the wall of the case.
The tab bundle of the negative tabs 82a and the negative conductive member 83 are joined by a welded portion 90. The welded portion 90 electrically connects all the negative tabs 82a and the negative conductive member 83. Although not shown, similarly on the positive side, the tab bundle of the positive tabs and the positive conductive member are welded by a welded portion. The welded portion electrically connects all the positive tabs and the positive conductive member.